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Homework Help: Momentum and collision

  1. Aug 5, 2011 #1
    1. a 7g bullet is fired into a 1.5kg ballistic pendulum. the bullet emerges from the block with a speed of 200m/s, and the block rises to a maximun height of 12cm. find the initial speed of the bullet and the kinetic energy lost of the bullet.
    answer: 528m/s, 835.7j

    2. mu+ mu = mv + mv
    0.007u + 1.5(0)= 0.007(200) + 1.5kg(v)
    how to know the final velocity of ballistic pendulum??

    help me.....please.....
    thank you
  2. jcsd
  3. Aug 5, 2011 #2


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    Homework Helper

    The pendulum's max height is 12cm, so its KE at the collision = PE at 12cm.

    so 0.5mv2=mg(0.12).
  4. Aug 5, 2011 #3
    i got it....thank you very much~
  5. Aug 5, 2011 #4
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